crypto/aead.c

   1 /*
   2  * AEAD: Authenticated Encryption with Associated Data
   3  *
   4  * This file provides API support for AEAD algorithms.
   5  *
   6  * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  */
  14
  15 #include <crypto/internal/aead.h>
  16 #include <linux/err.h>
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/rtnetlink.h>
  21 #include <linux/sched.h>
  22 #include <linux/slab.h>
  23 #include <linux/seq_file.h>
  24
  25 #include "internal.h"
  26
  27 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  28                             unsigned int keylen)
  29 {
  30         struct aead_alg *aead = crypto_aead_alg(tfm);
  31         unsigned long alignmask = crypto_aead_alignmask(tfm);
  32         int ret;
  33         u8 *buffer, *alignbuffer;
  34         unsigned long absize;
  35
  36         absize = keylen + alignmask;
  37         buffer = kmalloc(absize, GFP_ATOMIC);
  38         if (!buffer)
  39                 return -ENOMEM;
  40
  41         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  42         memcpy(alignbuffer, key, keylen);
  43         ret = aead->setkey(tfm, alignbuffer, keylen);
  44         memset(alignbuffer, 0, keylen);
  45         kfree(buffer);
  46         return ret;
  47 }
  48
  49 static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
  50 {
  51         struct aead_alg *aead = crypto_aead_alg(tfm);
  52         unsigned long alignmask = crypto_aead_alignmask(tfm);
  53
  54         if ((unsigned long)key & alignmask)
  55                 return setkey_unaligned(tfm, key, keylen);
  56
  57         return aead->setkey(tfm, key, keylen);
  58 }
  59
  60 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  61 {
  62         struct aead_tfm *crt = crypto_aead_crt(tfm);
  63         int err;
  64
  65         if (authsize > crypto_aead_alg(tfm)->maxauthsize)
  66                 return -EINVAL;
  67
  68         if (crypto_aead_alg(tfm)->setauthsize) {
  69                 err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
  70                 if (err)
  71                         return err;
  72         }
  73
  74         crypto_aead_crt(crt->base)->authsize = authsize;
  75         crt->authsize = authsize;
  76         return 0;
  77 }
  78 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  79
  80 static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
  81                                         u32 mask)
  82 {
  83         return alg->cra_ctxsize;
  84 }
  85
  86 static int no_givcrypt(struct aead_givcrypt_request *req)
  87 {
  88         return -ENOSYS;
  89 }
  90
  91 static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
  92 {
  93         struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
  94         struct aead_tfm *crt = &tfm->crt_aead;
  95
  96         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
  97                 return -EINVAL;
  98
  99         crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
 100                       alg->setkey : setkey;
 101         crt->encrypt = alg->encrypt;
 102         crt->decrypt = alg->decrypt;
 103         crt->givencrypt = alg->givencrypt ?: no_givcrypt;
 104         crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
 105         crt->base = __crypto_aead_cast(tfm);
 106         crt->ivsize = alg->ivsize;
 107         crt->authsize = alg->maxauthsize;
 108
 109         return 0;
 110 }
 111
 112 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 113         __attribute__ ((unused));
 114 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 115 {
 116         struct aead_alg *aead = &alg->cra_aead;
 117
 118         seq_printf(m, "type         : aead\n");
 119         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 120                                              "yes" : "no");
 121         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 122         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 123         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 124         seq_printf(m, "geniv        : %s\n", aead->geniv ?: "<built-in>");
 125 }
 126
 127 const struct crypto_type crypto_aead_type = {
 128         .ctxsize = crypto_aead_ctxsize,
 129         .init = crypto_init_aead_ops,
 130 #ifdef CONFIG_PROC_FS
 131         .show = crypto_aead_show,
 132 #endif
 133 };
 134 EXPORT_SYMBOL_GPL(crypto_aead_type);
 135
 136 static int aead_null_givencrypt(struct aead_givcrypt_request *req)
 137 {
 138         return crypto_aead_encrypt(&req->areq);
 139 }
 140
 141 static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
 142 {
 143         return crypto_aead_decrypt(&req->areq);
 144 }
 145
 146 static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 147 {
 148         struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
 149         struct aead_tfm *crt = &tfm->crt_aead;
 150
 151         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
 152                 return -EINVAL;
 153
 154         crt->setkey = setkey;
 155         crt->encrypt = alg->encrypt;
 156         crt->decrypt = alg->decrypt;
 157         if (!alg->ivsize) {
 158                 crt->givencrypt = aead_null_givencrypt;
 159                 crt->givdecrypt = aead_null_givdecrypt;
 160         }
 161         crt->base = __crypto_aead_cast(tfm);
 162         crt->ivsize = alg->ivsize;
 163         crt->authsize = alg->maxauthsize;
 164
 165         return 0;
 166 }
 167
 168 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 169         __attribute__ ((unused));
 170 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 171 {
 172         struct aead_alg *aead = &alg->cra_aead;
 173
 174         seq_printf(m, "type         : nivaead\n");
 175         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 176                                              "yes" : "no");
 177         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 178         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 179         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 180         seq_printf(m, "geniv        : %s\n", aead->geniv);
 181 }
 182
 183 const struct crypto_type crypto_nivaead_type = {
 184         .ctxsize = crypto_aead_ctxsize,
 185         .init = crypto_init_nivaead_ops,
 186 #ifdef CONFIG_PROC_FS
 187         .show = crypto_nivaead_show,
 188 #endif
 189 };
 190 EXPORT_SYMBOL_GPL(crypto_nivaead_type);
 191
 192 static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
 193                                const char *name, u32 type, u32 mask)
 194 {
 195         struct crypto_alg *alg;
 196         int err;
 197
 198         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 199         type |= CRYPTO_ALG_TYPE_AEAD;
 200         mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
 201
 202         alg = crypto_alg_mod_lookup(name, type, mask);
 203         if (IS_ERR(alg))
 204                 return PTR_ERR(alg);
 205
 206         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 207         crypto_mod_put(alg);
 208         return err;
 209 }
 210
 211 struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 212                                          struct rtattr **tb, u32 type,
 213                                          u32 mask)
 214 {
 215         const char *name;
 216         struct crypto_aead_spawn *spawn;
 217         struct crypto_attr_type *algt;
 218         struct crypto_instance *inst;
 219         struct crypto_alg *alg;
 220         int err;
 221
 222         algt = crypto_get_attr_type(tb);
 223         err = PTR_ERR(algt);
 224         if (IS_ERR(algt))
 225                 return ERR_PTR(err);
 226
 227         if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
 228             algt->mask)
 229                 return ERR_PTR(-EINVAL);
 230
 231         name = crypto_attr_alg_name(tb[1]);
 232         err = PTR_ERR(name);
 233         if (IS_ERR(name))
 234                 return ERR_PTR(err);
 235
 236         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 237         if (!inst)
 238                 return ERR_PTR(-ENOMEM);
 239
 240         spawn = crypto_instance_ctx(inst);
 241
 242         /* Ignore async algorithms if necessary. */
 243         mask |= crypto_requires_sync(algt->type, algt->mask);
 244
 245         crypto_set_aead_spawn(spawn, inst);
 246         err = crypto_grab_nivaead(spawn, name, type, mask);
 247         if (err)
 248                 goto err_free_inst;
 249
 250         alg = crypto_aead_spawn_alg(spawn);
 251
 252         err = -EINVAL;
 253         if (!alg->cra_aead.ivsize)
 254                 goto err_drop_alg;
 255
 256         /*
 257          * This is only true if we're constructing an algorithm with its
 258          * default IV generator.  For the default generator we elide the
 259          * template name and double-check the IV generator.
 260          */
 261         if (algt->mask & CRYPTO_ALG_GENIV) {
 262                 if (strcmp(tmpl->name, alg->cra_aead.geniv))
 263                         goto err_drop_alg;
 264
 265                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 266                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 267                        CRYPTO_MAX_ALG_NAME);
 268         } else {
 269                 err = -ENAMETOOLONG;
 270                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 271                              "%s(%s)", tmpl->name, alg->cra_name) >=
 272                     CRYPTO_MAX_ALG_NAME)
 273                         goto err_drop_alg;
 274                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 275                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 276                     CRYPTO_MAX_ALG_NAME)
 277                         goto err_drop_alg;
 278         }
 279
 280         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
 281         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 282         inst->alg.cra_priority = alg->cra_priority;
 283         inst->alg.cra_blocksize = alg->cra_blocksize;
 284         inst->alg.cra_alignmask = alg->cra_alignmask;
 285         inst->alg.cra_type = &crypto_aead_type;
 286
 287         inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
 288         inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
 289         inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
 290
 291         inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
 292         inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
 293         inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
 294         inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
 295
 296 out:
 297         return inst;
 298
 299 err_drop_alg:
 300         crypto_drop_aead(spawn);
 301 err_free_inst:
 302         kfree(inst);
 303         inst = ERR_PTR(err);
 304         goto out;
 305 }
 306 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 307
 308 void aead_geniv_free(struct crypto_instance *inst)
 309 {
 310         crypto_drop_aead(crypto_instance_ctx(inst));
 311         kfree(inst);
 312 }
 313 EXPORT_SYMBOL_GPL(aead_geniv_free);
 314
 315 int aead_geniv_init(struct crypto_tfm *tfm)
 316 {
 317         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 318         struct crypto_aead *aead;
 319
 320         aead = crypto_spawn_aead(crypto_instance_ctx(inst));
 321         if (IS_ERR(aead))
 322                 return PTR_ERR(aead);
 323
 324         tfm->crt_aead.base = aead;
 325         tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
 326
 327         return 0;
 328 }
 329 EXPORT_SYMBOL_GPL(aead_geniv_init);
 330
 331 void aead_geniv_exit(struct crypto_tfm *tfm)
 332 {
 333         crypto_free_aead(tfm->crt_aead.base);
 334 }
 335 EXPORT_SYMBOL_GPL(aead_geniv_exit);
 336
 337 static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
 338 {
 339         struct rtattr *tb[3];
 340         struct {
 341                 struct rtattr attr;
 342                 struct crypto_attr_type data;
 343         } ptype;
 344         struct {
 345                 struct rtattr attr;
 346                 struct crypto_attr_alg data;
 347         } palg;
 348         struct crypto_template *tmpl;
 349         struct crypto_instance *inst;
 350         struct crypto_alg *larval;
 351         const char *geniv;
 352         int err;
 353
 354         larval = crypto_larval_lookup(alg->cra_driver_name,
 355                                       CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
 356                                       CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 357         err = PTR_ERR(larval);
 358         if (IS_ERR(larval))
 359                 goto out;
 360
 361         err = -EAGAIN;
 362         if (!crypto_is_larval(larval))
 363                 goto drop_larval;
 364
 365         ptype.attr.rta_len = sizeof(ptype);
 366         ptype.attr.rta_type = CRYPTOA_TYPE;
 367         ptype.data.type = type | CRYPTO_ALG_GENIV;
 368         /* GENIV tells the template that we're making a default geniv. */
 369         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 370         tb[0] = &ptype.attr;
 371
 372         palg.attr.rta_len = sizeof(palg);
 373         palg.attr.rta_type = CRYPTOA_ALG;
 374         /* Must use the exact name to locate ourselves. */
 375         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 376         tb[1] = &palg.attr;
 377
 378         tb[2] = NULL;
 379
 380         geniv = alg->cra_aead.geniv;
 381
 382         tmpl = crypto_lookup_template(geniv);
 383         err = -ENOENT;
 384         if (!tmpl)
 385                 goto kill_larval;
 386
 387         inst = tmpl->alloc(tb);
 388         err = PTR_ERR(inst);
 389         if (IS_ERR(inst))
 390                 goto put_tmpl;
 391
 392         if ((err = crypto_register_instance(tmpl, inst))) {
 393                 tmpl->free(inst);
 394                 goto put_tmpl;
 395         }
 396
 397         /* Redo the lookup to use the instance we just registered. */
 398         err = -EAGAIN;
 399
 400 put_tmpl:
 401         crypto_tmpl_put(tmpl);
 402 kill_larval:
 403         crypto_larval_kill(larval);
 404 drop_larval:
 405         crypto_mod_put(larval);
 406 out:
 407         crypto_mod_put(alg);
 408         return err;
 409 }
 410
 411 static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
 412                                              u32 mask)
 413 {
 414         struct crypto_alg *alg;
 415
 416         alg = crypto_alg_mod_lookup(name, type, mask);
 417         if (IS_ERR(alg))
 418                 return alg;
 419
 420         if (alg->cra_type == &crypto_aead_type)
 421                 return alg;
 422
 423         if (!alg->cra_aead.ivsize)
 424                 return alg;
 425
 426         crypto_mod_put(alg);
 427         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 428                                     mask & ~CRYPTO_ALG_TESTED);
 429         if (IS_ERR(alg))
 430                 return alg;
 431
 432         if (alg->cra_type == &crypto_aead_type) {
 433                 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
 434                         crypto_mod_put(alg);
 435                         alg = ERR_PTR(-ENOENT);
 436                 }
 437                 return alg;
 438         }
 439
 440         BUG_ON(!alg->cra_aead.ivsize);
 441
 442         return ERR_PTR(crypto_nivaead_default(alg, type, mask));
 443 }
 444
 445 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 446                      u32 type, u32 mask)
 447 {
 448         struct crypto_alg *alg;
 449         int err;
 450
 451         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 452         type |= CRYPTO_ALG_TYPE_AEAD;
 453         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 454         mask |= CRYPTO_ALG_TYPE_MASK;
 455
 456         alg = crypto_lookup_aead(name, type, mask);
 457         if (IS_ERR(alg))
 458                 return PTR_ERR(alg);
 459
 460         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 461         crypto_mod_put(alg);
 462         return err;
 463 }
 464 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 465
 466 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 467 {
 468         struct crypto_tfm *tfm;
 469         int err;
 470
 471         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 472         type |= CRYPTO_ALG_TYPE_AEAD;
 473         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 474         mask |= CRYPTO_ALG_TYPE_MASK;
 475
 476         for (;;) {
 477                 struct crypto_alg *alg;
 478
 479                 alg = crypto_lookup_aead(alg_name, type, mask);
 480                 if (IS_ERR(alg)) {
 481                         err = PTR_ERR(alg);
 482                         goto err;
 483                 }
 484
 485                 tfm = __crypto_alloc_tfm(alg, type, mask);
 486                 if (!IS_ERR(tfm))
 487                         return __crypto_aead_cast(tfm);
 488
 489                 crypto_mod_put(alg);
 490                 err = PTR_ERR(tfm);
 491
 492 err:
 493                 if (err != -EAGAIN)
 494                         break;
 495                 if (signal_pending(current)) {
 496                         err = -EINTR;
 497                         break;
 498                 }
 499         }
 500
 501         return ERR_PTR(err);
 502 }
 503 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 504
 505 MODULE_LICENSE("GPL");
 506 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");